In recent years, there have been increasingly widespread organic EL panels including organic EL elements formed on a substrate. Commercialization of organic EL televisions seems to be nearing reality. Colorization methods of organic EL panels includes a known method of combining organic EL elements of the top emission type and a color filer (hereinafter, abbreviated as CF) substrate. According to this method, specifically, an organic EL substrate on which the organic EL elements are formed and the CF substrate on which colored layers are formed are adhered to each other via a resin layer such that the organic EL elements and the colored layers face each other. The organic EL elements of the top emission type employing the CF method fall into two types of organic EL elements emitting white light and organic EL elements each emitting light of any one of red (R), green (G), and blue (B) colors that are arranged in parallel. In the latter case, the CF substrate is used in order to increase the color purity of the organic EL elements emitting each emitting light of any one of R, G, and B colors to widen the color reproduction range of an organic EL panel.
Organic EL elements have an advantage of being highly visible resulting from self-luminescence, but have a disadvantage of being vulnerable to moisture. Accordingly, moisture intrusion from inside and outside an organic EL panel might cause generation of non-light emitting parts (dark spots) in a display region of the organic EL panel or decrease in luminance of the display region. Therefore, it is important how to remove moisture in order to put organic EL panels into practical use.
In view of this, there has conventionally been considered a method of providing a moisture absorbent layer in an organic EL panel. Known materials of the moisture absorbent layer include magnesium oxide, calcium oxide, and strontium oxide (Patent Literature 1). Magnesium oxide and so on are excellent in both transparency and moisture absorption property.